Pump running even if relay says "off"

Question

I have a relay that should be switched off when the analog value is too high by the Arduino code:

int digitalPin = 4; // for the relay
int analogPin = A0; // for the soil moisture sensor
int digitalVal; // digital readings
int analogVal; // analog readings
void setup()
{
    pinMode(digitalPin, OUTPUT);
    digitalWrite(digitalPin, LOW);
    Serial.begin(9600);
}
void loop()
{
    analogVal = analogRead(analogPin); // read the value returned by the soil moisture sensor
    if (analogVal < 400) { // if the soil moisture sensor returns a value < 400
        digitalWrite(digitalPin, HIGH); // The water pump waters the plant
    } else {
        digitalWrite(digitalPin, LOW); // The water pump stops watering
    }
    Serial.println(analogVal);
    delay(100);
}

But, as you can see on the video, despite going above the 400 threshold, having the relay pin switching off, it continues to pump.

Here is my architecture:

I just changed the relay to an Elegoo 4:

I am following this tutorial.